In cells capable of cellular respiration in a step often called the transition or bridge reaction, one is transported to the site the Krebs cycle by a large carrier molecule called . This step is important because it results in one complete "turn" of the cycle and the production of molecules from the Krebs cycle that can then be used in the electron transport chain.

The phylogenetic tree illustrates the relationship between humans and our closest living relatives. the tree was based on biochemical comparisons, including dna and amino acid sequences. according to the biomolecular data, we could infer that a) the four organisms do not have a common ancestor. b) humans are more closely related to chimps than any other apes. c) chimps are more closely related to gorillas than they are to humans. eliminate d) there is no evidence if any relationship between the four branches on the tree.

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.

Do plant cells perform cellular respiration?